First off, make sure to book your ceremony and reception locations before actually purchasing or renting your wedding dress. The season and location will have a large impact on the style of dress you will get. It has to be appropriate for the season and time of day, and the decor of the locations needs to be taken into consideration.
There are 6 basic silhouettes:
1. Princess or A-line - It's a full skirt, but not stiffly layered. The most universally flattering silhouette.
2. Ball gown/ Ballerina skirt/ Full skirt - The skirt is extremely stiff and full. The most romantic silhouette.
3. Empire waistline - A high waistline (just below the chest). A skirt that falls straight to the floor.
4. Column/ Sheath - A straight and narrow dress that hugs the body. It is tight-fitting. Very elegant and sophisticated. 
5. Trumpet/ Mermaid - It is tight at the waist and hips, fills out towards the feet. It creates an elegant and stylized look. 
6. Short - Perfect for an ultra-casual wedding or a civil ceremony. Others also choose to change into a shorter dress for the wedding reception. 
*all silhouette images are from http://www.marthastewartweddings.com/*
Dress necklines also differ. Here are some examples:
Halter neckline
Boat or Bateau neckline
Sweetheart neckline
And of course, another popular neckline is a V-neckline. The location of the ceremony will be an important factor as to how deep the V-neck can go.
*all neckline images are from Google*
I hope I was able to share some new information with you. More wedding-related posts to come soon. Happy Friday! :D
